//
// Created by 123 on 2024/12/31.
//
#include "iostream"
using namespace std;

//圆周率
const double PI = 3.14;

class Circle{

public:
    //属性
    int m_r;//半径
    //行为
    double calculateZC(){
        return 2* PI * m_r;
    }
};

int main052(){
    Circle circle;
    circle.m_r = 10;
    cout << "circle zhou chang == " << circle.calculateZC() << endl;
}